Required Assumptions, Demarcation, Limitations of Science

Nature of Science (per NGSS)

Scientific Investigations Use a Variety of Methods

Scientific Knowledge is Based on Empirical Evidence

Scientific Knowledge is Open to Revision in Light of New Evidence

Scientific Models, Laws, Mechanisms, and Theories Explain Natural Phenomena

Science is a Way of Knowing

Scientific Knowledge Assumes an Order and Consistency in Natural Systems

Science is a Human Endeavor

Science Addresses Questions About the Natural and Material World

Logical Statements - Inferences and Assumptions

Vocabulary:

Logic - the study of valid reasoning, usually relies on mathematics and computer science

Proposition - an idea that is proposed for consideration

Inference - a conclusion (decision about belief) made through reason and logic

Assumption - a conclusion/inference we have to accept as true in order to finish a logical statement (sometimes called a premise). Assumptions serve as the foundation of logical arguments (e.g., a building's foundation). As strange as it seems, all scientific knowledge is based on foundational assumptions. An honest scientists can admit that if any of these assumptions is even a little incorrect then even our strongest scientific theories and most carefully derrived laws could be flawed.

Example:

A: Socrates was a human (proposition)

B: Human beings are mortal (proposition)

C: Socrates was mortal (inference/conclusion which can be made if A and B are assumed to be true)

How did this mental process work? If A is true and B is true, then C must follow (also be true). If any assumption/premise is false, the logical conclusion is probably also false.

Required Assumptions of Modern Science

1. Reality

Realism (Materialism, Empiricism, and Rationalism) insists that a a single, objective reality exists that is shared by all observers.

If this were not so we could not possess shared truths, for each of us would have our own set of truths and laws of science would not apply in every situation.

2. Causality

There are natural causes for things that happen within our shared reality.

Science call these causes "laws of nature."

If this were not so we could not reliably explain, interpret, or predict objects or phenomena. We could not have "faith" in scientific knowledge. This remark is inflamatory to some, but the word faith means to have a high degree of trust, certainty, or confidence in the truth value of ideas or principles. See etymology of faith and belief.
Philosophy and religion are free to ask whether there is a Cause of all causes, but science views this line of questioning as exploring the supernatural. Supernatural means "above nature." Supernatural causes and principles cannot be observed, tested, proved or disproved by methods of science.

3. Uniformity

There is consistency in the causes (laws) that operate in the natural world.

We have to assume that natural laws have been operting in the same way and at the same rate since the birth of our universe (uniformitarianism) and that these laws apply everywhere in the universe.

4. Discoverability

These laws can be discovered and described by systematic observation and experimentation.

Where our biological senses are limitated technology can extend them, expanding the range of objects and phenomena that can be discovered.

Demarcation Problem - A False Assumption

Many falsely assume that there are clear boundaries between science and nonscience. No unified demarcation definition has been accepted among scientists and philosophers.

Philosophy of science attempts to study the relationships between science, pseudoscience, and nonscinece.

Some thinkers have identified demarcation as the central question in the philosophy of science, but more practical thinkers are concerned mainly with the positive results of scientific knowledge.

Historical Arguments:

Aristotle - to be scientific, one must deal with causes, logic, materialism, and certainty

Logical Positivism - statements that are not empirical observations or formal logic are meaningless

Skepticim - a degree of doubt must be maintained that the truth of ideas can be known

Replicability - an observation must be able to be repeated and be percieved by all observers to be scientific

Falsifiability - an idea is scientific if it is capable of being tested (verified or falsified) by experimentation or observation. That something is "falsifiable" does not mean it is false; rather, it means that if the statement were false, then its falsehood could be demonstrated. Many religious beliefs are not falsifiable and are therefor outside the scope of scientific knowledge.

Pseudoscience - the attempt to use scientific methods to study nonscientific topics [e.g., big foot, astrology, palm reading, ghosts, intelligent design, extra sensory perception (ESP), UFO's, etc.]

Nonscience is still important to human civilizations - examples: history, tradition, culture, literature, folklore and superstition, magic and mysticism, performing arts, philosophy, religion, visual arts, morals and social mores

Limitations of Scientific Knowledge

Philosophy of science seeks a deep understanding of what these underlaying assumptions mean and whether they are valid.

Our senses have biological limitations. Even technological devices for extending these limitations have their own limits of accuracy and range.

Our mental processing of sensory data is not always reliable. We are influenced by previous experience, biases, and degrees of attention. We not be interpreting the data correctly.

There are big differences between "scientific laws" and a "natural laws." Laws of science are the best possible descriptions of laws of nature, but it is impossible to know if we have considered all possible alternative explanations of natural phenomena.

Due to all these limitations, science knowledge is necessarily contingenet knowledge. We must admit that science is inherently uncertain. Scientific knowledge is not absolute truth. It is dependent on available evidence, circumstances, tools, and our imperfect analysis.